"Authorial illustration may be seen as a supplement to an illustrator’s less freely created commercial work, as a promotional tool, or as a platform for experimentation. It could be argued that the purpose of authorial illustration is to make the individual illustrator a more effective competitor in the market place. It could also be argued that authorial work demonstrates unfulfilled creative potential of the art of illustration. "
http://www.arts.ac.uk/events/13021.htm
